Sleep, or the lack of it.

Above is an example of what might be called a brave face. It is in fact my face after all of two hours' sleep. Such a terrifyingly brief amount of sleep - so short as to qualify as a nap - did not afflict me during May Week, when I was able to adjust to an almost totally nocturnal sleeping pattern (bed at 7am, breakfast at 5pm, yank on a dress and go), but in sunny Spain. The wonderful thing about Barcelona was that it never got properly cold; the terrible thing was that, being perpetually warm, staying out to the wee small hours is blissfully (or, as I discovered, painfully) easy to do.

As anybody who has seen my face after anything less than eight hours will tell you, I am a wreck on little sleep. By far the worst effect of sleep deprivation for me is its exacerbation of my already superhuman clumsiness: it feels as if I stumble through the day bumping into and/or swearing furiously at everything I see. All change, however, in Barcelona: though I still felt as if someone were walloping my head with a meat tenderiser, my physical state mysteriously did not translate into my usual underslept grumpiness. My baffled friends remarked somewhat warily on how well I was doing.

Yet my impossible joviality was not to last: by the time we'd made it (on our beautiful particoloured Dutch bikes which we'd schlepped uphill, panting furiously all the way) to the Park Guell, I was in the throes of fully-fledged mania, romping about parroting the idiotic poses of various snap-happy tourists. Above is not, I regret to say, the benign grin of a happy camper, but the sleep-deprived symptom of a cracked nut.